Odorants

ABSTRACT

The invention relates to compounds of the general formula                    
     in which R 1  to R 7  are, independently, H, methyl or ethyl, R 8 +R 9  together form methylene (—CH 2 —) or a single bond, or R 1 +R 2  together form —(CH 2 ) n —, with n being 3 or 4, or R 3 +R 5  or R 5 +R 7  represent methylene or a single bond; and the presence of at least one cyclopropane ring in the molecule is compulsory and the side chain can be saturated or contains one double bond in position α,β or β,γ, a process for the manufacture of these compounds, compounds used to perform the process and the use of these compounds as an odorant or as an ingredient of an odorant composition.

This is a divisional of U.S. application Ser. No. 09/295,841, filed Apr.21, 1999, now U.S. Pat. No. 6,162,954 which is a divisional of U.S.application Ser. No. 08/842,930, filed Apr. 9, 1997, now U.S. Pat. No.5,929,291.

The invention relates to novel odorants derived from campholenicaldehyde. In particular these are compounds of the general formula

in which R¹ to R⁷ are, independently, H, methyl or ethyl, R⁸+R⁹ togetherform methylene (—CH₂—) (i.e., forming a cyclopropane ring at the 3′, 4′position of the cyclopentane ring) or a single bond (thus resulting in adouble bond between 3′ and 4′ positions), or R¹+R² together form—(CH₂)_(n)—, with n being 3 or 4′, or R³+R⁵ or R⁵+R⁷ together formmethylene or a single bond; and the presence of at least onecyclopropane ring in the molecule is compulsory and the side chain canbe saturated or contains one double bond in position α,β or β,γ.

The novel compounds I may be obtained by a process comprising

a) mono- or dicyclopropanating a compound of formulae

or

b) reducing a compound of formulae

in a manner known per se, and, if desired, hydrogenating any double bondpresent in the compound I thereby obtained.

Possible routes to these novel compounds I starting from campholenicaldehyde and passing through the compounds II-IV are outlined inreaction schemes 1 and 2 hereafter.

The scheme 2 also shows a preferred route to the intermediate compoundIV.

For the sake of clarity these two schemes do not include the optionalalcohol protection and deprotection steps which can, preferably, beeffected before and after cyclopropanation (steps e) and f)respectively).

As shown in these schemes, the route from the known intermediates makesuse of known chemical transformations. These are:

a) aldol condensation, effecting elongation of the side chain, e.g. byreacting campholenic aldehyde with the reactant R²CH₂C(O)R¹ under basicconditions, e.g. using any organic or inorganic base,

b) Wittig-Horner alkenation of aldehydes and ketones using phosphoranesor phosphonates, e.g. triethylphosphonoacetate,

c) reduction of carboxylic esters to alcohols, e.g. using hydrides, e.g.LiAlH₄ in ether solvents,

d) reduction of carbonyl groups to saturated and unsaturated alcohols,e.g. using hydrides, e.g. borohydrides, e.g. NaBH₄ in alkanols,

e) cyclopropanation of C═C double bonds via methylene transfer, e.g.according to Simmon-Smith, e.g. using CH₂X₂, X being I or Br, and ametal (e.g. zinc-copper or zinc-silver) couple or diethylzinc ortrialkyl aluminium etc., optionally in the presence of an activator suchas acetyl bromide, TiCl₄ or ultrasound,

f) cyclopropanation by formation of and reductive dehalogenation of1,1-dihalocyclopropanes, e.g. with CHX₃ (X═Cl,Br) and a base,conveniently under phase transfer conditions, or with an alkali metalsalt or an alkyl ester of trichloroacetic acid and at elevatedtemperatures, followed by a reduction using, e.g. an alkali metal e.g.in THF or in ethanol, etc. Steps e) and f) lead to mono- anddicyclopropanated products depending on the reaction conditions and therelative reactivity of the C═C double bonds of IIa,

g) cyclopropanation of C═C double bonds of α,β-enones using ylides, e.g.using dimethylsulfonium or dimethyloxosulfonium methylide with orwithout solvent (e.g. THF, CH₂Cl₂, DMS, etc.),

h) deconjugation or deconjugative alkylation of α,β,-enones, e.g. byproviding first basic conditions, then reacting with R³X (X═Cl, Br, I)or H⁺, or, in the case of deconjugation, using an acid, or metal basedcatalysts,

i) conjugated addition of organometallics to α,β-enones, leading toβ-substituted carbonyl compounds, e.g. by the couple MeMgBr/CuI,conveniently in an ether as solvent,

j) reduction of α,β- or β,γ-enones to saturated alcohols, e.g. bycatalytic hydrogenation, such as H₂/Pt, using any inert organic solvent,

k) protection of the aldehyde function, e.g. as a dioxolane, beforecyclopropanation,

l) deprotection of the aldehyde function following cyclopropanation,e.g. using a strong acid, such as HCl/SiO₂,

m) protection and deprotection of the alcohol function, preferably insteps e) and f), e.g. as esters, ethers, silyl ethers, etc., seeProtective Groups in Organic Synthesis, T. Greene, P. G. M. Wuts, JohnWiley & Sons, Inc. New York, 1991.

As pointed out above, these transformations as exemplified in theexperimental part are known and their principles described in detail,e.g. in Comprehensive Organic Synthesis, Ed. Trost B. M., Fleming I.,Pergamon Press, Oxford, England 1991 (for a-h) and in Protective Groupsin Organic Synthesis, Greene T., Wuts P. G. M., John Wiley & Sons Inc.,New York, 1991 (for the protection/deprotection steps): namely in

a) vol 2, p 133 seq.

b) vol 1, p 755 seq.

c) vol 8, p 242 seq.

d) vol 8, p 1 seq.

e) vol 4, p 951 seq.

f) vol 4, p 999 seq.

g) vol 4, p 987

h) vol 3, p 21 seq.

i) vol 4, p 69 seq.

j) vol 8, p 523 seq.

k) p 175 seq.

l) p 175 seq.

m) p 10 seq.

Campholenic aldehyde is a most important starting material for thesynthesis of synthetic odorants exhibiting the odor profile ofsandalwood oil (see, e.g. U.S. Pat. Nos. 4,052,341, 4,6967,66).

No campholenic aldehyde derived cyclopentylbutanols or pentanols bearinga cyclopropane ring have however been published up to now.

Adding one or two such cyclopropane rings on campholenic aldehydederivatives modifies in particular the odor and substantivity (i.e.persistence of the odor) of the new derivatives. The new alcohols of thegeneral formula I exhibit various woody odor aspects; most of them exerta sandalwood odor, but some are also just woody/amber-like.

Among the novel compounds,[1-methyl-2-(1,2,2-trimethyl-bicyclo-[3.1.0]hex-3-ylmethyl)cyclopropyl]methanolhas the most natural, the strongest and most persistent sandalwood odor,superior to any existing synthetic (commercial) raw materials exhibitingsandalwood odor. All four stereoisomers of this compound contribute toits overall natural creamy, flowery, woody odor, but one of the(3″R)-diastereomers was found to constitute the main odor vector,approximatively 34 times more powerful than the second strongest amongthe synthesized stereoisomers.

The new cyclopropanated carbonyl compounds 1, 3, 4 as well as the newderivatives of the general formula IIb (with R⁴=Me) exhibit also usefulolfactory properties, their odor belonging also ta the amber/woody/sandalwood family of odors.

The present invention thus comprises also the compounds I, IIb, 3, 4 andtheir use as odorants, and a process to prepare compounds I.

The olfactory properties of the novel compounds harmonize with amultitude of natural or synthetic products widely used in compositions,in particular for generating middle and bottom notes, since the novelcompounds are endowed with very good tenacity.

The compounds I harmonize particularly well with all floral notes, inparticular with rose, iris, jasmine, ylang-ylang and narcissus notes.They also harmonize with balsamic or resinous dry-out notes such asstyrax, incense, and benzoin, and woody notes, such as oak moss or treemoss, patchouli and vetiver.

They thus provide most distinguished mixtures with a multitude ofnatural and synthetic raw materials.

Examples are:

natural products, such as, for example, tree moss absolute, basil oil,tropical fruit oils (such as bergamot oil, mandarine oil, etc.), mastixabsolute, myrtle oil, palmarosa oil, patchouli oil, petitgrain oil,wormwood oil, lavender oil, rose oil, jasmin oil or ylang-ylang oiletc.;

alcohols, such as farnesol, geraniol, linalool, nerol, phenylethylalcohol, rhodinol, cinnamic alcohol, cis-3-hexenol, menthol,(x-terpineol etc.;

aldehydes, such as citral, α-hexyl cinnamaldehyde, hydroxycitronellal,Lilial, (p-tert-butyl-α-methyl-dihydrocinnamaldehyde),methyl-nonylacetaldehyde, phenylacetaldehyde, anisaldehyde, vanillinetc.;

ketones, such as allylionone, α-ionone, β-ionone, isoraldein(isomethyl-α-ionone), verbenone, nootkatone, geranylacetone etc.;

esters, such as allyl phenoxyacetate, benzyl salicylate, cinnamylpropionate, citronellyl acetate, decyl acetate, dimethylbenzylcarbinylacetate, ethyl acetoacetate, cis-3-hexenyl isobutyrate, linalyl acetate,methyl dihydrojasmonate, styrallyl acetate, vetiveryl acetate, benzylacetate, cis-3-hexenyl salicylate, geranyl acetate etc.;

lactones, such as γ-undecalactone, δ-decalactone, pentadecan-15-olide(Exaltolid), 12-oxahexadecanolide (Hibiscolide), etc.;

acetals, such as Viridine (1,1-dimethoxy-2-phenylethane) etc.;

various components often used in perfumery, such as indole,p-menthane-8-thiol-3-one, methyleugenol, eugenol, anethol etc.

The percentages in which these derivatives are used may vary within widelimits ranging from a few parts per thousand in mass market products(e.g. cleaning, deodorant) up to a few per cent in alcoholic extractsfor (fine) perfumery. “Overdoses” of up to 20% of these derivatives comealso in consideration, and may thus impart very particular effects e.g.in combination with synthetic musks. However, even small amounts of thenovel compounds provide the odorant compositions with a rich sandalwoodor ambery/woody effect and increase the volume (strength anddiffusivity) and substantivity of their odor.

There is really no restriction regarding the type of formulations andthe destination of the actual finished product: thus, eau de cologne,toilet water, scented water, perfume, cream, shampoo, deodorant, soap,detergent powder, household cleaner, softener, etc. come intoconsideration.

The compounds I integrate into a multitude of compositions, e.g.oriental chypres, green and woody, floral leathers fougere tobaccos andfruity aldehydes, etc. They provide, via their olfactory note,exceptional richness and linkage between the dry-out constituents of thecompositions by providing more volume, warmth and roundness andaugmenting sandalwood and woody aspects.

Except where otherwise stated, all the campholenic aldehyde derivativesused as intermediates in the following examples were obtained startingfrom a ˜1:2 mixture of (S)-(−) and (R)-(+) campholenic aldehyde, bothenantiomers being available from the suitable α-pinene. However, thegeneral formula I should encompass both the pure isomers and mixtures ofconfigurational, namely opticals isomers, see carbons (1′,3′,4′,α,β,γ,δ)as well as the geometrical isomers (cis/trans isomerism), since allthese isomers can be generated using the appropriate starting materialsand synthetic methods.

The structure of the compounds described in the examples has been provenby their IR, NMR and mass spectra. All of them are colorless oils.

EXAMPLE 1

3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pentan-2-ol

34.6 g (0.13 mol) of diiodomethane was added to a stirred suspension of17.0 g (0.26 mol) of zinc powder and 2.58 g (26 mmol) of cuprouschloride in 70 ml of anhydrous diethyl ether. The reaction mixture wassonicated for 30 minutes in a standard ultrasound bath. A solution of21.0 g (0.10 mol) of3-methyl-5-(2,2,3-trimethylcyclopent-3-enyl)-pentan-2-ol in 20 ml of thesame solvent was added dropwise (exothermic reaction) and the'sonication(reflux) continued for further 7 hours. The reaction mixture was pouredinto 330 ml of 1N hydrochloric acid and extracted with 300 ml oftert-butyl methyl ether. The organic layer was washed with 2×150 ml ofbrine, dried (MgSO₄) and concentrated in vacuo to give 29 g of brownishoil which after distillation using a 10 cm Vigreux column at. 100-105°C./0.08 Torr and subsequent flash chromatography with 300 g of silicagel (eluent: hexane/MTBE 5:1) yielded 10.6 g (47% yield) of3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0] hex-3-yl)pentan-2-ol.

IR (neat): 3348, 3059, 2998, 2960, 2929, 2856, 1463, 1379, 1363, 1299,1098, 1013, 924 cm⁻¹.

Odor: sandalwood, amber, woody, creamy.

EXAMPLE 2

2,3-Dimethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)butan-1-ol

a) 2.3-dimethyl-4-(2 2.3-trimethylcyclopent-3-enyl)butanal

100 ml (0.30 mol) of methylmagnesium bromide solution in diethyl etherwas added to 60.0 g (0.32 mol) of cuprous iodide suspended in 350 ml ofthe same solvent at −10° C., followed by addition of 52.0 g (0.27 mol)of 2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-enal dissolved in300 ml of anhydrous diethyl ether at 0° C. and stirring at the sametemperature was continued for 0.5 hours. The reaction mixture wastreated with 200 ml of 1.0 N hydrochloric acid, decanted and the organiclayer was washed with 2×300 ml of brine, dried (MgSO₄) and concentratedin vacuo. The residue was purified by flash chromatography on silica gel(eluent: hexane/MTBE 15:1) to give 28.2 g (50% yield) of2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)butanal.

IR (neat): 3036, 2957, 2930, 2874, 2834, 2700, 1725, 1460, 1383, 1360,1015, 798 cm⁻¹.

b) 2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)butan-1-ol

A solution of 18.0 g (86 mmol) of2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)butanal in 50 ml ofethanol was added dropwise at 0° C. to 45.0 g (0.11 mol) of sodiumborohydride suspended in 200 ml of the same solvent. After 18 hours ofstirring at room temperature 100 ml of 1.0 N aqueous hydrochloric acidwas added dropwise at 0° C. The reaction mixture was extracted with 200ml of MTBE, the extract washed with with 3×100 ml of brine, dried(MgSO₄) and concentrated in vacuo. The residue was distilled at 82-86°C./0.1 Torr to give 14.1 g (78% yield) of2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)butan-1-ol.

IR (neat): 3338, 3037, 2956, 2928, 2834, 1461, 1381, 1360, 1024, 798cm⁻¹.

Odor: sandalwood, amber, fruity, floral.

c) 2.3-dimethyl-4-(1,2.2-trimethylbicyclo[3.1.0] hex-3-yl)butan-1-ol

1.0 g (3.7 mmol) of diiodomethane was added to the stirred suspension of0.97 g (15 mmol) of zinc powder and 0.15 g (1.5 mmol) of cuprouschloride in 20 ml of anhydrous diethyl ether. The reaction mixture wassonicated for 15 minutes in a standard ultrasound bath, then 0.60 g (2.8mmol) of 2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)butan-1-ol wasadded and the sonication (reflux) continued for further 2 hours. Afteraddition of 1.68 g (6.3 mmol) more of diiodomethane followed by further4 hours of sonication the reaction mixture was diluted with 50 ml oftert-butyl methyl ether and filtered over Celite. The filtrate waswashed with 50 ml of 1N aqueous hydrochloric acid and 50 ml of brine,dried (MgSO₄) and concentrated in vacuo to give 1.3 g of brownish oil.The purification by flash chromatography on silica gel (eluent: hexane/MTBE 4:1) gave 0.30 g (48% yield) of2,3-dimethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)butan-1-ol.

IR (neat): 3335, 3036, 2955, 2928, 1462, 1381, 1360, 1115, 1024, 798cm⁻¹.

Odor: woody, sandalwood, floral.

EXAMPLE 3

3,3-Dimethyl-5-(1 2,2-trimethylbicyclo[3.1.0]hex-3-yl)pentan-2-ol

7.5 g (33 mmol) of3,3-dimethyl-5-(1,2,2-trimethylcyclopent-3-enyl)pentan-2-ol was treatedaccording to Example 1 with 3.25 g (50 mmol) of zinc dust, 0.50 g (5mmol) of cuprous chloride and 13.4 g (50 mmol) of diiodomethane exceptfor shorter sonication time which was 20 minutes for the preparation ofZn/Cu couple and 4 hours for the cyclopropanation. Flash chromatographyof the crude product (6.8 g of yellow oil) on 200 g of silica gel(eluent: hexane/MTBE 5:1) yielded 1.9 g (24% yield) of3,3-dimethyl-5-(1,2,2-trimethyl-bicyclo[3.1.0]hex-3-yl)pentan-2-ol.

IR (neat): 3389, 3060, 2960, 2934, 2869, 1464, 1363, 1095, 1014, 911cm⁻¹.

Odor: woody, sandalwood.

EXAMPLE 4

[1-Methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]methanol

200 g (1.15 mol) of dibromomethane and 1 ml (0.013 mol) of acetylbromide were added successively to a suspension of 85 g (1.3 mol) ofzinc powder and 12 g (83 mmol) of finely ground cuprous bromide in 250ml of anhydrous diethyl ether. The reaction mixture was stirred untilits color changed from grey to black (30 minutes). After addition of 50g (0.26 mol) of(E)-2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol dissolvedin 50 ml of the same solvent (Et2O), in 10 minutes (the exothermicreaction triggers a smooth reflux of ether), and 2 drops of TiCl₄,stirring at room temperature was continued for further 7 hours. Thereaction mixture was then diluted with 300 ml of MTBE, filtered throughCelite, the filtrate washed with 200 ml of ice-cold 0.1N HCl and 3×200ml of brine, dried (MgSO₄), concentrated in vacuo and distilled rapidly(0.1 Torr) to give 39 g of a yellowish oil containing 81% of[1-methyl-2-(1,2,2-trimethyl-bicyclo[3.1.0]hex-3-yl-methyl)cyclopropyl]methanol(yield 55%). Further purification by distillation using a 15 cm Vigreuxcolumn under 0.08 Torr afforded 27.4 g (48% yield) of olfactorily pureproduct. GC purity >91%, b.p. 104-105° C./0.08 Torr. More product couldbe recovered from 4.5 g of rejected (66% pure) fractions.

IR (neat): 3335, 3058, 2952, 2926, 2867, 1463, 1450, 1385, 1362, 1028,1014 cm⁻¹.

Odor: sandalwood, very natural, floral, creamy, powdery, very strong andlong-lasting.

EXAMPLE 5

(3″R)-[1-Methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]-methanol;2:3 mixture of 2 diastereomers

The same reaction conditions as in Example 4 applied to(R,E)-2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol,obtained from (R)-(+)-campholenic aldehyde, resulted in a 2:3 mixture oftwo diastereomers, tentatively (1′R,1″S,2′R,3″R,5″R)- and(1′S,1″S,2′S,3″R,5″R)-[1-methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl] methanol.

[α]²² _(D)=+28.50 (c 0.95, ethanol)

Odor: typically sandalwood, very strong and long-lasting GC-sniffolfactory analysis of this mixture carried out with a DB-FFAP column:peak 1 (first eluted, minor): lactonic, with a sandalwood aspect, peak 2(major): sandalwood, creamy, warm, strong.

EXAMPLE 6

(3″S)-[1-Methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]-methanol;2:3 mixture of 2 diastereomers

The same reaction conditions as in Example 4 applied to(S,E)-2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol,obtained from (S)-(−)-campholenic aldehyde, resulted in a 2:3 mixture oftwo diastereomers, tentatively (1′S,1″R,2′S,3″S,5″S)- and(1′R,1″R,2′R,3″S,5″S)-[1-methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]methanol.

[α]²² _(D)=−26.5° (c 0.54, ethanol)

Odor: woody, rosy, sandalwood

GC-sniff olfactory analysis of this mixture carried out as in Example 5:peak 1 (first eluted, minor): floral, rosy, milky, sandalwood, peak 2(major): lactonic, lily of the valley.

EXAMPLE 7

[1-Ethyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]methanol

20.8 g (0.10 mol) of(E)-2-ethyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol was treatedaccording to Example 1 with 52.0 g (0.80 mol) of zinc dust, 8.0 g (81mmol) of cuprous chloride and 70.0 g (0.40 mol) of dibromomethane exceptfor different sonication time which was 22 hours for thecyclo-propanation step. Flash chromatography of the crude product onsilica gel (eluent: hexane/MTBE 4:1) yielded 9.7 g (41% yield) of[1-ethyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]methanol.

IR (neat): 3333, 3058, 2961, 2927, 2869, 1462, 1362, 1033, 1015 cm⁻¹.

Odor: sandalwood, fruity, creamy/milk-like, very long-lasting.

EXAMPLE 8

1-[1-Methyl-2-(1,2.2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]ethanol

22.0 g (0.34 mol) of zinc powder was added under nitrogen to avigorously stirred solution of 1.0 g (5.0 mmol) of copper acetate in 80ml of acetic acid at 90° C. After 5 minutes of stirring at thistemperature the red-grey Zn/Cu couple was decanted, washed successivelywith 20 ml of acetic acid and 3×30 ml of diethyl ether and suspended in200 ml of diethyl ether. The suspension was treated with a small crystalof iodine and 56.2 g (0.21 mol) of diodomethane and stirring wascontinued for further 30 minutes. 5.2 g (25 mmol) of(E)-3-methyl-5-(2,2,3-trimethylcyclopent-3-enyl)pent-3-en-2-ol dissolvedin 20 ml of diethyl ether was added dropwise and the reaction mixturewas heated at reflux for the following 40 hours. The usual treatment(cf. Example 1) yielded 6.8 g of yellow oil which was purified by flashchromatography on silica gel (eluent: hexane/MTBE 4:1) to give 0.9 g(15% yield) of1-[1-methyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]ethanol.

IR (neat): 3364, 3058, 2955, 2927, 2868, 1463, 1362, 1300, 1100, 1104,1073, 1015, 931, 901 cm⁻¹.

Odor: sandalwood, amber, camphor, minty.

EXAMPLE 9

3-[2-(1,2,2-Trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]butan-2-ol

10.4 g (50 mmol) of(E)-3-methyl-5-(2,2,3-trimethylcyclopent-3-enyl)pent-4-en-2-ol wastreated according to Example 1 with 17.0 g (0.26 mol) of zinc dust, 2.58g (26 mmol) of cuprous chloride and 34.6 g (0.13 mol) of diodomethaneexcept for different sonication time which was 46 hours for thecyclopropanation step. Flash chromatography of the crude product onsilica gel (eluent: hexane/MTBE 4:1) yielded 7.8 g (64% yield) of3-[2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]butan-2-ol.

IR (neat): 3361, 3059, 2962, 2928, 2869, 1463, 1362, 1091, 1012, 910cm⁻¹.

Odor: floral, woody, dry, fatty, lactonic, rosy.

EXAMPLE 10

[1-Methyl-2-(2,2 3-trimethylcyctopent-3-enylmethyl)cyclopropyl]methanol

2.0 g (12 mmol) of dibromomethane and 3 drops of acetyl bromide wereadded to the stirred suspension of 9.8 g (0.15 mol) of zinc powder and1.5 g (10 mmol) of finely ground cuprous bromide in 40 ml of anhydrousdiethyl ether. After 30 minutes more stirring at room temperature asolution of 9.7 g (50 mmol) of2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)-butan-1-ol in 30 ml of thesame solvent was added quickly and stirring at room temperaturecontinued for further 7 hours. During this period more 19.0 g (0.11 mol)of dibromomethane was added in 4 portions. The reaction mixture wasfiltered and the filtrate washed successively with 100 ml of 1Nhydrochloric acid and 100 ml of water, dried (MgSO₄) and concentrated invacuo to give 7.4 g of yellow oil containing 44% of the startingmaterial and 34% of the product. 21.7 g (0.25 mol) of manganese(II)oxide was added to oxidize the former. After 7 hours stirring at roomtemperature, the reaction mixture was filtered over Celite, the filtrateconcentrated in vacuo and the residue purified by flash chromatographyon silica gel (eluent: hexane/MTBE 4:1) to give 1.5 g (14% yield) of[1-methyl-2-(2,2,3-trimethyl-cyclopent-3-enylmethyl)cyclopropyl]methanol.

IR (neat): 3346, 3034, 2953, 2928, 2865, 1693, 1463, 1447, 1382, 1359,1030, 1013, 798 cm⁻¹.

Odor: creamy, lactonic, sandalwood.

EXAMPLE 11

1- [2-(2,2,3-Trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanol

a) 1-[2-(2,2,3-Trimethylcyclopent-3-enylmethyl)cylopropyl]ethanone

3.08 g (64 mmol) of 50% oil suspension of sodium hydride was washed with50 ml of hexane and dried in vacuo. 14.1 g (63 mmol) oftrimethylsulfoxonium iodide and 70 ml of dimethyl sulfoxide weresuccessively added at room temperature (ice bath) under nitrogen andwith mechanical stirring which was then continued for further 30minutes. A solution of 10.6 g (55 mmol) of5-(2,2,3-trimethylcyclopent-3-enyl)pent-3en-2-one in 30 ml of DMSO wasadded quickly and the reaction mixture was stirred at room temperaturefor 2 hours, poured on 200 g of icy 1N aqueous hydrochloric acid andextracted with 200 ml of MTBE.

The extract was washed with 2×210 ml of brine, dried (MgSO₄) andevaporated in vacuo to give 9.8 g of brown oil which was distilled at78° C./0.08 Torr and further purified by flash chromatography on silicagel (eluent: hexane/MTBE 7:1) to yield 2.8 g (25% yield) of1-[2-(2,2,3-trimethyl-cyclopent-3-enylmethyl)cyclopropyl]ethanone.

IR (neat): 3035, 3001, 2955, 2928, 2865, 1699, 1441, 1401, 1360, 1172,1013, 964, 866, 799 cm⁻¹.

Odor: woody, cedar, 5-ionone aspect, floral, sandalwood.

b) 1-[2-(2,2,3-Trimethylcyclopent-3-enylmethyl) cyclopropyl]ethanol

1.5 g (7.3 mmol) of1-[2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]-ethanonedissolved in 5 ml of ethanol was added to a suspension of 0.50 g (13mmol) of sodium borohydride in 30 ml of the same solvent under nitrogenat 15° C. The reaction mixture was stirred at room temperature forfurther 2 hours. After addition of 50 ml of 1N aqueous hydrochloric acidit was extracted with 200 ml of MTBE, the organic layer washed with2×200 ml of brine, dried (MgSO₄) evaporated in vacuo and bulb-to-bulbdistilled to give 1.3 g of1-[2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanol (87%yield).

IR (neat): 3352, 3060, 3035, 2955, 2928, 2865, 1652, 1463, 1360, 1106,1083, 1022, 968, 798 cm⁻¹.

Odor: sandalwood, green.

EXAMPLE 12

1-[1-Methyl-2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanol

a) 1-[1-Methyl-2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanone

11.3 g (55 mmol) of3-methyl-5(2,2,3-trimethylcyclopent-3enyl)-pent-3-en-2-one wascyclopropanated with 14.1 g (63 mmol) of trimethylsulfoxonium iodide and3.08 g (64 mmol) of 50% oil suspension of sodium hydride according toExample 11a giving 5.4 g (45% yield) of1-[1-methyl-2(2,2,3trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanone.

IR (neat): 3035, 2955, 2931, 2865, 2834, 1689,1463, 1444, 1383, 1359,1280, 1152, 1139, 1013, 824, 798 cm⁻¹.

Odor: woody, dry, anisic, incense.

b)1-[1-Methyl-2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanol

Sodium borohydride reduction of 3.0 g (13.6 mmol) of1-[1-methyl-2-(2,2,3trimethyl-cyclopent-3-enylmethyl)cyclopropyl]ethanone from Example 12aaccording to Example 11b gave 1.6 g of1-[1-methyl-2-(2,2,3-trimethylcyclopent-3-enylmethyl)cyclopropyl]ethanol(53% yield).

IR (neat): 3366, 3055, 3035, 2955, 2929, 2865, 2834, 1463, 1382, 1359,1303, 1107, 1075, 1045, 1012, 902, 930, 799 cm⁻¹.

Odor: sandalwood, slightly phenolic.

EXAMPLE 13

1-(2.2.3-Trimethylcyclopent-3-enylmethyl)spiro[2.4]heptan-4-ol

a) 1-(2,2,3-Trimethylcyclopent-3-enylmethyl)spiro[2.4]heptan-4-one

13.0 g (60 mmol) of2-[2-(2,2,3-trimethylcyclopent-3-enyl)ethylidene]-cyclopentanone wascyclopropanated with 16.2 g (74 mmol) of trimethyl-sulfoxonium iodideand 3.6 g (75 mmol) of 50% oil suspension of sodium hydride according toExample 11a to give 4.9 g (35% yield) of1-(2,2,3-trimethylcyclopent-3-enylmethyl)spiro[2.4] heptan-4-one.

IR (neat): 3035, 2956, 2929, 2865, 1726, 1437, 1390, 1360, 1257, 1170,1118, 1013, 798 cm⁻¹.

Odor: woody, cedar, camphor/earthy.

b) 1-(2,2,3-Trimethylcyclopent-3-enylmethyl)spiro[2,4]heptan-4-ol

Sodium borohydride reduction of 3.8 g (16 mmol) of1-(2,2,3-trimethyl-cyclopent-3-enylmethyl)spiro[2.4]heptan-4-oneaccording to Example 11b gave 2.3 g of1-(2,2,3-trimethylcyclopent-3-enylmethyl)spiro[2.4]heptan-4-ol (61%yield).

IR (neat): 3361, 3036, 2954, 2930, 2865, 1652, 1444, 1382, 1359, 1080,1023, 1012, 960, 798 cm⁻¹.

Odor: sandalwood, milky, green, sweet.

EXAMPLE 14

(1,2,2-Trimethylbicyclo[3.1.0]hex-3-yl)ethanal

a) 2-(1,2,2-Trimethylbicyclo[3.1.0]hex-3-ylmethyl)-[1.3]dioxolane

150 ml (0.15 mol) of 1.0 M solution of diethylzinc in hexane was addedto 500 ml of 1,2-dichloroethane under nitrogen. After having added 66.0g (0.23 mol) of diiodomethane, while maintaining the temperature at15-20° C. (ice bath), the solution was stirred at room temperature for30 minutes, then 20.0 g (0.10 mol) of2-(2,2,3-trimethylcyclopent-3-enylmethyl)-[1,3]dioxolane was addeddropwise at 25° C. and the stirring continued for three hours. Thereaction mixture was treated with 100 ml of 20% aqueous potassiumcarbonate, the organic layer separated and the aqueous layer extractedwith diethyl ether. The combined organic phases were dried (MgSO₄) andevaporated in vacuo. 22 g of the crude product was distilled at 95°C./0.1 Torr to give 14.9 g (71% yield) of2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)-[1,3]dioxolane used inthe next step without further purification

b) (1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethanal

A mixture of 11.0 g (52 mmol) of2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)-[1,3]-dioxolane, 80 mlof acetone, 40 ml of water, 1.5 ml of conc. hydrochloric acid and 10 gof silica gel was stirred at reflux for 4 hours. After filtration, thesolution was diluted with diethyl ether, washed with water, dried(MgSO₄) and evaporated in vacuo. Kugelrohr distillation of the residuegave 6.8 g (79% yield) of(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethanal.

IR (neat): 3061, 3000, 2956, 2929, 2869, 2717, 1726, 1464, 1365, 1018cm⁻¹.

Odor: green, ketonic, bitter.

EXAMPLE 15

2-Methyl-4-(1 1,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal

30 g (0.18 mol) of (1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethanal wasadded to 5.0 ml (24 mmol) of stirred 5.4 M methanolic solution of sodiummethylate diluted with 40 ml of methanol. 35 g (0.61 mol) ofpropionaldehyde was added at 25° C. with cooling during 10 minutes, thereaction mixture stirred at room temperature for 1.5 hours, neutralizedwith acetic acid and the solvent removed in vacuo. The residue wasdissolved in 100 ml of ether, washed with 3×80 ml of water, dried(MgSO₄) and evaporated in vacuo. Purification by Kugelrohr distillationat 94° C./0.1 Torr followed by flash chromatography on silica gel(eluent: hexane/MTBE 4:1) gave 16.0 g (43% yield) of2-methyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal.

IR (neat): 3060, 2998, 2954, 2927, 2868, 169.0, 1644, 1463, 1451, 1363,1014 cm⁻¹.

Odor: woody, fatty, sandalwood.

EXAMPLE 16

2-Methyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-en-1-ol

0.5 g (10 mmol) of sodium borohydride dissolved in 5 ml of water wasadded portionwise to the solution of 5.0 g (24 mmol) of2-methyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal in 20 ml ofethanol maintained at 0° C. Stirring was continued for 1 hour at 0-5°C., then acetone was added to destroy the excess of hydride. Thereaction mixture was poured on 100 ml of water, extracted with 2×100 mlof ether, dried (MgSO₄) and evaporated in vacuo. Kugelrohr distillationof the residue at 160° C./0.1 Torr gave 4.5 g (90% yield) of2-methyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-en-1-ol.

IR (neat): 3312, 3059, 2998,2951,2927, 2867, 1463, 1386, 1362, 1074,1013 cm⁻¹.

Odor: woody, sandalwood, slightly camphor.

EXAMPLE 17

2-Ethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal

The condensation of 20.0 g (0.12 mol) of(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethanal with 17.0 g (0.24 mol) ofbutyraldehyde catalyzed with sodium ethoxide prepared from 0.25 g ofsodium in 35 ml of ethanol, according to Example 15, gave 9.98 g (38%yield) of 2ethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal.

IR (neat): 3060, 2963, 2870, 2711, 1738, 1689, 1641, 1463, 1364, 1151,1065, 1014, 798 cm⁻¹.

Odor: fatty, lactonic, green, sandalwood.

EXAMPLE 18

2-Ethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-en-1-ol

Sodium borohydride reduction of 10.0 g (45 mmol) of2-ethyl-4-(1,2,2-timethylbicyclo[3.1.0]hex-3-yl)but-2-enal as in Example16 gave 6.4 g (64% yield) of2-ethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-en-1-ol.

IR (neat): 3316, 3061, 3000, 2962, 2930, 2869, 1709, 1463, 1363, 1299,1045, 1013 cm⁻¹.

Odor: woody, cedar, sandalwood.

EXAMPLE 19

3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-one

560 g (8.5 mol) of butan-2-one and 234 g (1.4 mol) of(1,2,2-trimethyl-bicyclo[3.1.0]hex-3-yl)ethanal were added to 48 g (0.75mol) of potassium hydroxide dissolved in 500 ml of water and 1.4 1 ofmethanol. The reaction mixture was stirred overnight with ice-bathcooling, poured into 3 l of water and extracted with diethyl ether. Theextract was washed with water, dried (MgSO₄) and evaporated in vacuo.The residue was distilled at 108° C./0.1 Torr to give 140 g (45% yield)of 3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-one.

IR (neat): 3060, 2999, 2954, 2927,2868, 1670, 1641, 1463, 1364, 1287,1088, 1014 cm⁻¹.

Odor: woody, lactonic, fatty, sandalwood.

EXAMPLE 20

3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-ol

0.37 g (10 mmol) of sodium borohydride was added portionwise withcooling to the solution of 3.7 g (10 mmol) of cerium trichloride and 2.0g (10 mmol) of3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-one in 25ml of methanol. After 5 more minutes water was added and the mixtureextracted with diethyl ether, dried (MgSO₄) and evaporated in vacuo.Purification by flash chromatography on silica gel (eluent: hexane/MTBE9:1) gave 1.3 g (58% yield) of3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-ol.

IR (neat): 3340, 3059, 2998, 2963, 2928, 2868, 1463, 1363, 1298, 1079,1013, 892 cm⁻¹.

Odor: sandalwood, natural, green, lactonic.

EXAMPLE 21

3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-one 66.0 gof potassium tert-butoxide dissolved in 850 ml of tetrahydrofuran wasadded to the solution of 140 g (0.64 mol; 70% pure) of3-methyl-5-(1,2,2-trimethylbicyclo-[3.1.0]hex-3-yl)pent-3-en-2-one in850 ml of the same solvent at 0° C. After 30 minutes of stirring at roomtemperature the reaction mixture was poured on 1 l of aqueous ammoniumchloride solution. After the usual workup the crude product was purifiedby flash chromatography on silica gel (eluent: hexane/MTBE 19:1) to givethree fractions: 5.1, 28.1 and 22.3 g containing respectivly 36, 78, and92% of 3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-one(40% yield).

IR (neat): 3059, 2958, 2929, 2868, 1715, 1452, 1361, 1166, 1013, 976cm⁻¹.

Odor: slightly cedar, tobacco.

EXAMPLE 22

3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol

2.2 g (10 mmol) of3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-one wasreduced as in Example 16 to give 1.9 g (85% yield) of3-methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol.

IR (neat): 3360, 3058, 2998, 2962, 2927, 2868, 1451, 1362, 1091, 1012,976 cm⁻¹.

Odor: sandalwood, floral.

EXAMPLE 23

3.3-Dimethyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-one

5.0 g (43 mmol) of potassium tert-butoxide dissolved in 50 ml oftetrahydrofuran was added to the solution of 8.7 g (40 mmol) of3-methyl-5-(1,2,2-trimethylbicyclo-[3.1.0]hex-3-yl)pent-3-en-2-one in 50ml of the same solvent at −40° C. After 5 minutes of stirring at −35° C.7.0 g (45 mmol) of methyl iodide was added rapidly and stirringcontinued at −20° C. for 10 minutes. The reaction mixture was poured on200 ml of water and worked up as usual. Flash chromatography of thecrude product (silica gel; eluent: hexane/MTBE 9:1) followed byKugelrohr distillation at 150° C./0.1 Torr gave 7.3 g (78% yield) of3,3-dimethyl-5-(1,2,2-trimethylbicyclo[3.1.0] hex-3-yl)pent-4-en-2-one.

IR (neat): 3036, 2955, 2930, 2864, 2841, 1711, 1463, 1444, 1382, 1359,1122, 979, 797 cm⁻¹.

Odor: woody, musty.

EXAMPLE 24

3,3-Dimethyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol

6.5 g (28 mmol) of3,3-dimethyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-onewas reduced as in Example 16 to give 6.0 g (92% yield) of3,3-dimethyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol.

IR (neat): 3396, 3035, 2955, 2931, 2865, 2840, 1462, 1381, 1359, 1100,981, 910, 797 cm⁻¹.

Odor: sandalwood, woody.

EXAMPLE 25

5-(1,2.2-Trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol and 1-[2-(12.2-Trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]propan-2-ol

a) Acetic acid 5-(2.2.3-trimethylcyclopent-3-enyl)pent-4-en-2-yl Ester

50 g (0.48 mol) of acetic anhydride was added dropwise to the solutionof 78.6 g (0.40 mol) of5-(2,2,3-trimethylcyclopent-3-enyl)pent-4-en-2-ol and 5.0 g of4-dimethylaminopyridine in 150 ml of MTBE. The reaction mixture wasstirred at 50-55° C. for 1 hour, treated with 0.5 l of water andextracted with 3×150 ml of hexane. The combined organic layers wereneutralized with aqueous potassium hydrogen carbonate solution, washedwith water, dried (MgSO₄) and evaporated in vacuo. The residue (102 g)was distilled at 80-81° C./0.2 Torr to give 89.8 g (95% yield) of aceticacid 5-(2,2,3-trimethyl-cyclopent-3-enyl)pent-4-en-2-yl ester.

b) Acetic Acid 5-(1.2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ylEster and Acetic Acid1-[2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]propan-2-ylEster

30 g (0.17 mol) of dibromomethane was added dropwise under nitrogen tothe suspension of 100 g (1.5 mol) of zinc powder and 15 g (0.10 mol) ofcuprous bromide in 700 ml of diethyl ether. 1 ml of acetyl bromide wasadded and the reaction mixture was stirred for 30 minutes beforeaddition of 59 g (0.25 mol) of the acetate prepared in a). 250 ml (1.44mol) of dibromomethane was then added dropwise during 6.5 hours andstirring was continued for 1.5 hours at 40° C. After the usual work-up,69 g of crude product was fractionated on a 25 cm packed column at 0.1Torr:

fraction 1 b.p. 76-80° C.: 7.2 g and

fraction 2 b.p. 80-83° C.: 24.5 g containing respectively 60 and 81% ofacetic acid 5-(1,2,2-trimethylbicyclo[3.1.0] hex-3-yl)pent-4-en-2-ylester; fraction 3 b.p. 87-102° C.: 11.3 g of acetic acid1-[2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]propan-2-ylester.

c) 5-(1,2,2-Trimethylbicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol

Fraction 2 of Example 25b was hydrolized with 9.8 g of potassiumhydroxide in 130 ml of methanol and 10 ml of water at 45-65° C. for 1hour. The reaction mixture was neutralized with conc. citric acid andextracted with diethyl ether. After the usual work-up the crude productwas distilled (Kugelrohr) at 1500C/0.1 Torr to give 20 g (98% yield) of5-(1,2,2-trimethyl-bicyclo[3.1.0]hex-3-yl)pent-4-en-2-ol.

IR (neat): 3344, 3059, 2999, 2962, 2926, 2867, 1463, 1362, 1126, 1075,1013, 975, 942 cm⁻¹.

Odor: woody, cedar, sandalwood aspect, camphor.

d) 1-[2-(1,2,2-Trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]propan-2-ol

Fraction 3 of Example 25b was hydrolized according to the same reactionconditions as in Example 25c to give1-[2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)cyclopropyl]propan-2-ol in97% yield. IR (neat): 3347, 3059, 2998, 2962, 2926, 2868, 1464, 1362,1127, 1090, 1012, 949 cm⁻¹.

Odor: woody, dry, amber.

EXAMPLE 26

[1,2-Dimethyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]-methanol

a) 2,3-Dimethyl-4-(2.2 3-trimethylcyclopent-3-enyl)but-2-enoic acidethyl ester

47.6 g (0.20 mol) of triethyl 2-phosphonopropionate was added dropwiseunder nitrogen to a cooled and stirred suspension of 4.8 g (0.20 mol) ofsodium hydride in 300 ml of THF and stirring continued for 30 min. atroom temperature. After addition of 30 g (0.18 mol) of1-(2,2,3-trimethylcyclopent-3-enyl)propan-2-one, prepared fromcampholenic aldehyde as known per se, and 46 hours of more stirring, thereaction mixture was poured into 400 ml of ice-cold 1N hydrochloric acidand extracted with 2×300 ml of MTBE. The extract was washed with 5×350ml of brine, dried (MgSO₄) and concentrated in vacuo. The distillationat 90-97° C./0.065-0.075 Torr yielded 13 g of the product which wasfurther purified by flash chromatography on silica gel (eluent:hexane/MTBE 15:1) to give 6.4 g (14% yield) of2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-enoic acid ethylester.

IR (neat): 3036, 2955, 2932, 2866, 1714, 1630, 1462, 1445, 1361, 1282,1247, 1206, 1095, 1031, 798, 771 cm⁻¹.

b) 2,3-Dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol

5.3 g (21 mmol) of the ester obtained in a), diluted with 50 ml ofanhydrous diethyl ether, was added to a stirred suspension of 0.8 g (21mmol) of lithium aluminium hydride in 70 ml of the same solvent and thereaction mixture was refluxed for 4 hours. 1.5 ml of water, 1.5 ml of15% aqueous sodium hydroxide solution and again 1.5 ml of water wassuccessively added at room temperature. After filtration and extractionwith 2×250 ml of MTBE, the combined organic phases were washed with 100ml of 2M sodium hydroxide solution and 2×100 ml of brine, dried (MgSO₄)and concentrated in vacuo to give 4.4 g (quantitative yield) of2,3-dimethyl-4-(2,2,3-trimethylcyclopent-3-enyl)but-2-en-1-ol. Theproduct was used in the next step without further purification.

IR (neat): 3325, 3036, 2954, 2930, 2865, 1653, 1445, 1381, 1360, 1011,798 cm⁻¹.

c)[1,2-Dimethyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclo-propyl]methanol

4.0 g (19 mmol) of the alcohol of b) was cyclopropanated according toExample 1 with 9.8 g (150 mmol) of zinc powder, 1.48 g (15 mmol) ofcuprous chloride and 26.8 g (100 mmol) of methylene-iodide except forthe shorter reaction time, namely 2 hours. After repeated flashchromatography on silica gel (eluent: hexane/MTBE 5:1) of the crudeproduct, a sample of 0.26 g (6%) of olfactorily pure[1,2-dimethyl-2-(1,2,2-trimethylbicyclo[3.1.0]hex-3-ylmethyl)cyclopropyl]methanolwas obtained.

IR (neat): 3352, 3058, 2953, 2929, 2869, 1463, 1452, 1379, 1363, 1087,1029, 1014 cm⁻¹.

Odor: Woody, sandalwood, lactonic, warm, musky.

EXAMPLE 27

[1-Methyl-2-[1-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethyl]cyclopropyl]methanol

a) 2-Methyl-4-(2,2,3-trimethylcyclopent-3-enyl)pent-2-enal

60.0 g (0.36 mol) of 2-(2,2,3-trimethylcyclopent-3-enyl)propionaldehyde,prepared from campholenic aldehyde as known per se, and 42.0 g (0.72mol) of propanal was added successively during 15 min and 2 hours,respectively, to the sodium methylate solution prepared from 0.83 g ofsodium and 200 ml of anhydrous methanol, at 10° C. The reaction mixturewas stirred at 10° C. for 2 hours and at room temperature for thefollowing 42 hours. After addition of 5 ml of acetic acid the solventwas evaporated in vacuo at the temperature maintained below 50° C. Theresidue was diluted with 500 ml of MTBE, washed with 2×200 ml of brine,dried (MgSO₄), concentrated in vacuo and distilled at 76-95° C./0.1 Torrto give 28.1 g (38%) of2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)pent-2-enal. An analyticalsample was prepared by flash chromatography on silica gel (eluent:hexane/MTBE 12:1).

IR (neat): 3039, 2960, 2934, 2872, 2702, 1725, 1458, 1386, 1362, 1118,1025, 806 cm⁻¹.

b) 2-Methyl-4-(2. 2 3-trimethylcyclopent-3-enyl)pent-2-en-1-ol

10.0 g (48 mmol) of2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)pent-2-enal was reducedaccording to the procedure of Example 11b) to give, after distillationat 91° C./0.09 Torr, 6.5 g (65%) of2-methyl-4-(2,2,3-trimethylcyclopent-3-enyl)pent-2-en-1-ol.

IR (neat): 3323, 3035, 2956, 2929, 2867, 2833, 1658, 1445, 1382, 1358,1063, 1010, 871, 802 cm⁻¹.

c)[1-Methyl-2-[1-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethyl]cyclopropyl]-methanol

A solution of 5.15 g (25 mmol) of the alcohol of Example 27b in 20 ml ofdiethyl ether was added rapidly to the Zn/Cu couple prepared by 15 minsonication of the suspension of 13.0 g (200 mmol) of zinc powder, 2.0 g(20 mmol) of cuprous chloride and 5.0 g (19 mmol) of methylene iodide in30 ml of the same solvent. 21.8 g (81 mmol) more of methylene iodide wasadded dropwise during 4 hours and stirring at 30° C. was continued for 2more hours. The reaction mixture was diluted with 200 ml of diethylether, filtered through Celite, washed with 150 ml of ice-cold 1Nhydrochloric acid and 2×100 ml of brine, dried (MgSO₄) and concentratedin vacuo. 6.8 g of the crude product was purified by flashchromatography on silica gel (eluent: hexane/MTBE 4:1) to give 1.25 g(21% yield) of[1-methyl-2-[1-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)ethyl]cyclopropyl]methanol.

IR (neat): 3345, 3058, 2955, 2929, 2869, 1450, 1382, 1362, 1030, 1017,980, 866, 833 cm⁻¹.

Odor: Sandalwood, creamy, lactonic, tobacco, woody.

EXAMPLE 28

Fresh - Floral - Woody Accord for consumer goods parts per weightAldehyde C12 MNA 0.3 Aldehyde iso C11 0.7 cis-Jasmone 1 3-cis-Hexenol 3Eucalyptus globulus oil China 5 Undecavertol 5 Stemone 5 Rose oxyde 5Nonadyl 10 Viridine 10 Anther 10 Geranyl acetate 15 Iso E super 20 Allylcyclohexylpropionate 20 Dihydro myrcenol 30 β-Ionone synt. 30Citronellol 40 Verdyl propionate 40 α,α-Dimethylphenethyl acetate 40Agrumex 50 Lilial 60 Isoraldeine 70 70 Fixolide 70 Bergamot oil 80Verdyl acetate 80 p-tert-Butylcyclohexyl acetate 100 Hexylcinnamicaldehyde 150 Compound of Example 4 10 Dipropylene glycol 40  50 Total1000 1000

The novel compound gives to the accord a creamy, sweet, rich sandalwoodeffect and increases the volume and the substantivity of the perfumecomposition.

EXAMPLE 29

Floral - Ambery Feminine Accord parts per weight Cardamone oil Ceylon  2Indolene 10% DPG  3 Stemone  3 Aldehyde C11 10% DPG  3 Allyl amylglycolate  4 Cassione (4-Benzo-1,3-dioxo-5-yl-but-2-one)  5 10% DPGCoumarine  5 Citronellyl acetate  5 Cyclal C 10% DPG  5 cis-Jasmone 10%DPG  6 Geraniol pure  8 Benzyl acetate 10 Benzyl salicylate 20 Patchoulioil 25 Vanillin 25 3-cis-Hexenyl salicylate 30 Linalyl acetate 40 Iso Esuper 40 Phenyl ethyl alcohol 45 Mandarin oil (reconstitution) 50Linalool 60 Bergamot oil 80 Galaxolide 50% DEP 200  Hedione 210 Compound of Example 4 10 Dipropylene glycol 106   116 1000  1000

The novel compound gives to the accord a creamy, sweet, rich sandalwoodeffect and increases the volume and the substantivity of the perfumecomposition.

For the exact definition of the trivial names mentioned above, seeFlavour and Fragrance Materials 1995, Allured Publishing Co., CarolStream, Ill. 60188-2787, USA.

What is claimed is:
 1. Compounds of formula 3:

wherein R¹, R², R⁴ and R⁶ are H, methyl or ethyl, or R¹+R² together form—(CH₂)_(n)—, with n being 3 or
 4. 2.2-Methyl-4-(1,2,2-trimethylbicyclo[3.1.0] hex-3-yl)but-2-enal. 3.2-Ethyl-4-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)but-2-enal. 4.3-Methyl-5-(1,2,2-trimethylbicyclo[3.1.0]hex-3-yl)pent-3-en-2-one.
 5. Anodorant composition comprising at least one compound of formula 3:

wherein the radicals R¹, R², R⁴, and R⁶ are H, methyl or ethyl, or R¹+R²together form —(CH₂)_(n)—, with n being 3 or 4.